VENERIDAE 415 



more distinct concentric threads on the outside, and with fine crenulations 

 along the inside of the ventral margins of the valves. Interior white, com- 

 monly with a pinkish blush. Dredged from 30 to 50 fathoms and brought 

 in by shrimp fishermen. Uncommon. 



Subgenus Hysteroconcha P. Fischer 1887 

 Pitar dione Linne Royal Comb Venus 



Plate 39f 



Texas to Panama and the West Indies. 



I to 1% inches in length, characterized by its violet and purple-white 

 colors and 2 radial rows of long spines at the posterior end of the valve. A 

 common species washed ashore in Texas. The closely resembling species, 

 Fitar lupanaria Lesson, occurs in the Pacific from Lower California to Peru. 



Genus Gouldia C. B. Adams 1845 



Shell less than V2 inch in length; beaks minute; lunule long, bounded 

 by an impressed line; no escutcheon. With concentric or reticulate sculpture. 

 Anterior lateral teeth present. This genus is put in the separate subfamily 

 Circinae by some workers. 



Goiddia cerina C. B. Adams Serene Gould Clam 



North Carolina to south half of Florida and the West Indies. 



% inch in length, solid, trigonal in shape, beaks in the center, high and 

 very small; lunule long, bounded by an impressed line; no escutcheon. 

 Sculpture reticulate in which the fine, concentric ribs predominate. The 

 radial ribs are stronger anteriorly. Color white, uncommonly with purplish 

 or brownish flecks. A common species from shallow water to 95 fathoms. 



Genus Callista Poll 1791 

 Subgenus Costacallista Palmer 1927 



Callista ezicymata Dall Glory-of-the-Seas Venus 



Plate 39i 



North Carolina to south half of Florida, Texas and the West Indies. 



I to 1 34 inches in length, fairly thin, oval, with about 50 slightly flat- 

 tened, concentric ribs which have a short dorsal and long ventral slope, 

 and separated by a narrow, sharp groove. Color glossy-white to waxy pale- 

 brown, with clouds and zigzag markings of reddish brown. No escutcheon. 

 Margins rounded. A beautiful and rare species dredged from 25 to no 

 fathoms. 



